Question
Hi Jim,
I have an approximately 35-year-old Chinese Elm in my front yard. It is probably 50-60 feet tall, and the trunk is about 5 feet in diameter. It is healthy, but probably needs to be "topped out" in the near future. It's only been "topped out" once in it's lifetime, about 10-12 years ago. There are 2 places where the roots are in the way of my lawn mowing. I have to mow around them. These particular roots are both about 3-5 inches in diameter and are protruding out from the surface about 3-5 inches.. My question is:
Can I cut out the sections of roots that are in the way, without killing the tree? I would have to remove about a 3-5 foot section of each one. They are positiond on opposite sides of the tree from one another.
Please let me know your thoughts.
Thanks,
Dave

Answer
"Shaving" the roots will cause fungi to enter and may cause die back of the tree's foliage and/or death to the tree. You can cover the roots with sand as long as you do not cover the root with more than 3 inches of sand. More than that may cause the roots to die from compaction of the air spaces in the soil. You can then let the grass grow through the sand.




Topping a tree is never a good thing. This is a pet peeve of mine.  

Topping is the senseless practice of indiscriminately removing a majority of a tree's branches. Topping violates most commonly accepted methods of proper pruning; it is an assault on the health and beauty of your trees. Five important facts to remember about tree topping:  

Topping will not make trees safe; it actually creates hazardous trees.
Topping makes a tree more susceptible to storm damage.
Topping makes a tree more prone to insect and disease problems.
Topping is: abuse, vandalism, dangerous, expensive, mutilation, ugly.
Topping is a waste of money.

Here is a web link to the bad things about "topping out"

http://www.plantamnesty.org/stoptopping/5reasons.aspx